1. a ball is dropped from a tower. from whose reference point is the ball approaching the observer?
a)a person standing on top of the tower

b)a person on the ground driving rapidly away from the tower.

c)a person in an airplane flying above the tower

d)a person standing on the ground beneath the tower

Option-(D): The more obvious answer to the question will be,a person standing on the ground beneath the tower.

Explanation:

The observer:

When a ball is dropped from a certain point or height,H it will be perceived differently by a number of people and it will all depend on the position of those individuals inside the specific time frame in which they exists. So, after evaluation of all the options  we get to know that it will be the person who is standing on the ground that will be able to likely observe the event.

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.

less than one you can't create energy